Chicken wing dissection: homologous bones in a wing and a human arm · Concept Studio

The idea

A bird wing and a human arm are built on the same pattern of one bone, then two bones, then a group of small bones, although they do different jobs, which is anatomical evidence that tetrapods share a common ancestor.

Safety card

Medium riskA teacher supervises

Setting: In a school laboratory, with a teacher supervising, under the school's risk assessment. Not for home.

Hazards

Raw poultry carries bacteria such as Salmonella and Campylobacter that cause food poisoning
Sharp scissors and broken bone ends
Latex allergy

Controls

Nitrile gloves; no eating or drinking; hands kept away from the face; all tissue and surfaces treated as contaminated and cleaned then disinfected; hands washed with soap afterwards
Blunt-tipped scissors with cuts made away from the body; no scalpels for learners
Wings kept refrigerated until the lesson and used the same day; tissue double-bagged to the bin
Anyone who declines to dissect observes and records, or works from photographs

Note

Animal tissue: follow the NSW Department of Education guidance on using animals in Stage 4 and 5 (dissection of whole dead animals or parts purchased from a butcher, supermarket, fish market or abattoir is a permitted teaching activity; no live animal may be acquired or bred for the sole purpose of dissection) and use the Queensland CARA biological activities guideline as a hygiene reference only; it is Queensland policy, and the permission to dissect comes from the NSW guidance. Handle raw poultry as the NSW Food Authority advises. Record a RiskAssess risk assessment.

What you need

A whole raw chicken wing with its tip, one per pair, bought from a supermarket or butcher (the NSW Department of Education guidance on using animals in Stage 4 and 5 permits dissection of animal parts purchased from a butcher or supermarket)
Dissecting tray or board, blunt-tipped scissors, forceps, blunt probe, ruler
Nitrile gloves, safety glasses, paper towel, detergent and disinfectant, a lined bin for tissue
A labelled diagram of the human arm skeleton: humerus, radius, ulna, 8 carpals, 5 metacarpals, 14 phalanges

How to do it

Identify the three segments of the wing from the outside: the part nearest the body, the flat middle part and the tip. Bend each joint and record which way it moves.
With the scissors, cut the skin along the length of the part nearest the body and peel it back; continue along the middle part. Keep gloved hands and tools away from the face.
Find the muscles on the two sides of the part nearest the body. Pull each one in turn with the forceps and record which way the middle part moves.
Clear the muscle from the part nearest the body and count its bones; do the same for the middle part, count its bones and note which is thicker.
Open the tip and count the digits and any bones that are fused together.
Measure the length of each exposed bone. Beside the human arm diagram, record the pattern for each limb and label the matching bones: humerus, radius, ulna, wrist and hand.
Write a claim, evidence and reasoning paragraph: does the shared bone pattern support common ancestry, and why does a shared function not explain it, given that the wing and the arm do different jobs?
Bag the tissue for the bin, clean and disinfect the tray, tools and bench, remove gloves and wash hands with soap.

What you should see

The part nearest the body holds one bone, the humerus; the middle part holds two, the radius and the thicker ulna; the tip holds a fused hand bone (the carpometacarpus) carrying three reduced digits, where the human hand has 8 carpals, 5 metacarpals and 14 phalanges. The muscles on the two sides of the humerus work as an opposing pair: one bends the elbow and the other straightens it. The same one-bone, two-bone sequence in a limb used for flight and a limb used for grasping is the pattern the University of California Museum of Paleontology Understanding Evolution site presents as evidence of the common ancestry of all tetrapods. The learner knows it worked when all three segments are opened, the bones are counted and matched on the diagram, and the argument rests on the bone pattern rather than on what the limb is used for.

What changes

This activity lists no variables to change, measure and keep the same.

Common misconceptions

Each of these ideas is wrong, and the activity is a chance to test it.

Different animals have similar bones because they do the same job; the wing and the arm do different jobs yet share the same bones.
Humans evolved from birds, or birds from humans; both inherited the limb plan from a shared ancestor.
Evolution builds each new structure from nothing; it modifies structures that were already present.

Curriculum references

The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.

Science 7–10 Syllabus (2023)SC5-GEV-01 SC5-WS-01 SC5-WS-08
Australian Curriculum v9AC9S10U02AC9S10I03AC9S10I07

Sources

The pages the author read to write this activity.